A. Field of the Disclosure
The present disclosure relates generally to pipe fittings.
B. Background
Earth movement that occurs during floods, landslides, mudslides, seismic events, and other natural and man-made disasters applies forces to conduits that cause them to fail. Products may tolerate these forces via a number of methods, including inherent material flexibility or joint flexibility. When the conduit material is relatively inflexible, as is the case with iron or steel pipe, forces may be reduced to an acceptable level by adding joint deflection and/or displacement.
Several approaches have been taken to resist failure due to soil movement of pipes and other conduits. One approach has been to provide a restrained joint (as opposed to a flexible one), but such restrained joints cannot resist extremely high axial or radial forces, as they are designed to prevent axial displacement and deflection instead of allowing such movement without failure. One attempted solution was the placement of a crushable element between a fixed weld and a locking ring segment so that the crushable element could absorb excessive forces to prevent disengagement; however, when the crushable element fails under excessive forces, in some cases the remnants of the crushable element can damage components of the joint, such as gaskets. Other designs have involved locking rings placed around a pipe spigot internal to a pipe socket, which are complicated to install, and even more difficult to disassemble and service after installation.
Consequently there is a long-felt need in the art for a pipe joint that resists separation under extreme stresses that can be easily installed and disassembled.